عنوان مقاله [English]
Hydrogels, due to their hydrophilic network and their high ability to absorb and retain large amounts of water are widely used in medicine, industry, and the environment for different applications such as tissue engineering, drug delivery, and adsorption of pollutants. As well as synthetic raw materials, hydrogels can be fabricated using bio-based compounds with non-toxicity, high biocompatibility, and biodegradability. Recently, the Diels-Alder cycloaddition reaction has been used to produce hydrogels with improved properties. Following the Diels-Alder reaction, a six-membered cycle is formed by the [4+2] cycloaddition between an electron-rich diene and an electron-deficient dienophile. To perform this reaction, no catalyst is required, and moreover no by-products are produced. Other important features of the Diels-Alder reactions include insensitivity to a variety of functional groups and also thermal reversibility through the retro Diels -Alder reaction. However, using the Diels-Alder reaction, it is possible to produce biocompatible bio-based hydrogels with an enhanced performance like stimulus-responsivity, self-healing property, and the in-situ forming ability for a variety of applications. In this review, after a brief introduction to hydrogels, the recent reports about the utilization of the click Diels-Alder reactions in the synthesis of various bio-based hydrogels for different applications will be discussed.